File オブジェクトLink to this heading#

File クラスLink to this heading#

class File(file_object)Link to this definition#

File クラスは、Python の file object に Django 特有の追加機能を付け加えた薄いラッパーです。内部的でファイルを表現する必要がある場合には、Django はこのクラスを使います。

File オブジェクトには次の属性とメソッドを持ちます。

nameLink to this definition#

MEDIA_ROOT からの相対パスを含むファイル名です。

sizeLink to this definition#

bytes で表されたファイルサイズ。

fileLink to this definition#

このクラスがラッピングしている、素の file object クラスです。

modeLink to this definition#

ファイルの読み込み/書き込みのモードです。

open(mode=None)Link to this definition#

Open or reopen the file (which also does File.seek(0)). The mode argument allows the same values as Python's built-in open().

When reopening a file, mode will override whatever mode the file was originally opened with; None means to reopen with the original mode.

It can be used as a context manager, e.g. with file.open() as f:.

__iter__()Link to this definition#

Iterate over the file yielding one line at a time.

chunks(chunk_size=None)Link to this definition#

Iterate over the file yielding "chunks" of a given size. chunk_size defaults to 64 KB.

This is especially useful with very large files since it allows them to be streamed off disk and avoids storing the whole file in memory.

multiple_chunks(chunk_size=None)Link to this definition#

Returns True if the file is large enough to require multiple chunks to access all of its content give some chunk_size.

close()Link to this definition#

Close the file.

In addition to the listed methods, File exposes the following attributes and methods of its file object: encoding, fileno, flush, isatty, newlines, read, readinto, readline, readlines, seek, tell, truncate, write, writelines, readable(), writable(), and seekable().

The ContentFile classLink to this heading#

class ContentFile(File)Link to this definition#

The ContentFile class inherits from File, but unlike File it operates on string content (bytes also supported), rather than an actual file. For example:

Code

from django.core.files.base import ContentFile

f1 = ContentFile("esta frase está en español")
f2 = ContentFile(b"these are bytes")

The ImageFile classLink to this heading#

class ImageFile(file_object)Link to this definition#

Django provides a built-in class specifically for images. django.core.files.images.ImageFile inherits all the attributes and methods of File, and additionally provides the following:

widthLink to this definition#

Width of the image in pixels.

heightLink to this definition#

Height of the image in pixels.

Additional methods on files attached to objectsLink to this heading#

Any File that is associated with an object (as with Car.photo, below) will also have a couple of extra methods:

File.save(name, content, save=True)Link to this definition#

Saves a new file with the file name and contents provided. This will not replace the existing file, but will create a new file and update the object to point to it. If save is True, the model's save() method will be called once the file is saved. That is, these two lines:

Code

>>> car.photo.save('myphoto.jpg', content, save=False)
>>> car.save()

are equivalent to:

Code

>>> car.photo.save('myphoto.jpg', content, save=True)

Note that the content argument must be an instance of either File or of a subclass of File, such as ContentFile.

File.delete(save=True)Link to this definition#

Removes the file from the model instance and deletes the underlying file. If save is True, the model's save() method will be called once the file is deleted.